COMPLEX STRUCTURE AND REGULATION OF THE P16 (MTS1) LOCUS

The p16 gene (P16, MTS1, CDKN2) encodes a negative regulator of the ce ll cycle. Molecular genetic techniques have been used to explore the r ole of p16 in normal development and cancer. Two transcripts derived f rom the p16 gene with distinct protein coding potentials are described . The previously undescribed transcript form has the same exons 2 and 3 as the p16-encoding mRNA but contains a different exon 1. The human p16 transcripts are detected in various tissues, and the ratio of the transcripts is regulated in both a tissue-specific and cell cycle-spec ific manner. The P16-derived mRNAs are probably generated from separat e promoters, and transcription from one of the promoters appears to be regulated, at least in part, by the retinoblastoma gene product.